Metering pump



June 29, 1965 K. D. HUGHES METERING PUMP 3' Sheets-Sheet 1 Filed June 4, 1962 INVENTOR BY lfsu/vsrnfl. HUGHES ATTORNEYS 'June 29, 1965 K. b. HUGHES HETERING PUMP E w m i M 8 D 0 n w m ME A a u MW 3 V 8 2 6 m 4 e m J d e m June 29, 1965 Filed June 4, 1962 lOO/;'; OUTPUT 46 K. D. HUGHES 3,191,542

METERING PUMP 3 SheeTzs-Sheet a :31 tjNEuTRAL,sucTloN sTARTs SUCTION SUCTION E:|36SUCTlON r SUCTION STOPS NEUTRAL,

DISCHARGE sTARTs DISCHARGE C:] DISCHARGE DISCHARGE F; DISCHARGE STOPS, NEUTRAL NEUTRAL NEUTRAL NEUTRAL EUTRAL 11:] NEUTRAL,NEUTRAL NEUTRAL NEUTRAL NEUTRAL NEUTRAL lNVE/VT'OR KE/v/vEmD. Husnss ATTORNEYS United States Patent 3,191,542 METERING PUM? Kenneth D. Hughes, 3244 Blaisdell, Minneapolis, Minn. Filed June 4,196 2, Ser. No. 199,810 6 Claims. (Cl. 103-162) This invention is a novel metering pump in which the pistons are moved full stroke regardless of the output being delivered by the pump. It is also novel in having the pistons of the pump driven by wobble plates and rotating the body of the pump carrying the pistons between relatively stationary cam plates one of which may be moved, however, with relation to the other in order to adjust pump output. The movement of the movable cam plate may be carried out while the pump is in operation by means of a control member geared to the cam plate and extending to the exterior of the pump. Another point of novelty in the pump is having the pumping structure completely sealed away from the balance of the interior of the pump case so that the entire mechanism may run in lubricant without in any way limiting materials to be pumped.

Proportioning or metering pumps having variable flow that have been known heretofore have always involved structure which varied the eifective length of stroke of the pistons. This was accomplished in any of several ways. In every instance, however, the effective stroke of the previously known metering pump pistons is reduced for reduced pump output and at minimal pump capacity the movement of the piston is so slight as to require supercharging the pump in order to make sure that the cylinder receives a full charge. The reason for this appears to be simply that the inertia of the liquid being pumped is such that insufficient flow can be obtained with a very slight piston movement and hence supercharging is necessary for accurate metering. Also, most of the previously known metering pumps could be varied in capacity only by stopping the unit during adjustment.

Accordingly, it is the principal object of this invention to provide an improved metering pump.

It is another object of this invention to provide a metering pump that employs a full stroke of all the pumping elements regardless of the extent to which the capacity of the pump is being used.

It is a further object of this invention to provide a metering pump in which the pump does not require supercharging even at minimal discharge rates.

Yet another object of this invention is to provide a metering pump the output of which may be varied while the pump is in operation.

It is a still further object of this invention to provide a metering pump that may be lubricated readily.

Other and further objects of the invention are those inherent and apparent in the apparatus as described, pictured and claimed.

To the accomplishment of the foregoing and related ends, this invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principles of the invention may be employed.

The invention will be described with reference to the drawings in which corresponding numerals refer to the same parts and in which:

FIGURE 1 is a longitudinal section through the pump with portions broken away to illustrate construction more fully;

FIGURE 2 is a cross section of the device taken on the line and in the direction of the arrows 22 of 3,191,542 Patented June 29, 1965 FIGURE 1; broken lines show continuation of gear teeth drawn only in sufficient number to illustrate interaction;

FIGURE 3 is a fragmentary section taken on the line and in the direction of the arrows 3-3 of FIGURE 1; FIGURE 3 is drawn to a larger scale than that used in FIGURES 1 and 2;

FIGURE 4 is a sectional view taken on the line and in the direction of the arrows 4-4 of FIGURE 3; and

FIGURE 5 is a diagrammatic representation of three different output cycles of the pump.

Referring to the drawings and first to FIGURE 1, the pump is housed in any suitable housing here shown as a cylindrical casing 16. One end of casing 10 is closed by an end plate 11 conventionally secured to casing 10 as by the cap screws 12. A suitable gasket 14 may be provided between the end plate and the casing to make it liquid tight. The other end of housing 10 is closed by a similar but not identical end plate 15 secured with the screws 16 and having the gasket 17.

The end plate 11 supports an outlet pipe 18 by reason of its being press fitted into the plate. The interior end of the pipe 18 carries a bearing 19 which is prevented from moving toward the end plate 11 by suitable means such as the snap ring 20. Similar structure is seen at the other end of the housing Where the pipe 21 is press fitted into end plate 15, and pipe 21 has on its inner end the bearing 22 held in place by snap ring 24.

Rotatably supported by the bearings 19 and 22 is the pump body member 25. The shoulders on the two bearings 19 and 22 stabilize the body 25 longitudinally within the pump housing 10. A ring gear 26 is conventionally secured on one end of the pump body 25 and meshes with the spur gear 27 carried by shaft 28. Shaft 28 is jour nalled in a suitable bearing 29 and is sealed at the end wall 15 by a suitable sealing member 30, which is conventional in nature. Whenever shaft 28 is rotated, therefore, the pump body 25 rotates within the casing 10 supported by the two pipes 18 and 21. Suitable seals of conventional nature, as shown at 31 for pipe 21 and 32 for pipe 18, provide a dynamic liquid tight seal between the pipes 18 and 21 and pump body 25.

Within the pump body are formed a series of cylinders such as that indicated at 34 and within which pistons such as those designated 35 and 36 are seen. Each of the pistons is provided with a dynamic seal such as O- ring 37 for piston 35 which seal is duplicated for all pistons. These pistons are prevented from rotating within the cylinders formed in pump body 25 by suitable means such as the lug 38 sliding in the groove 39 formed in the pump body with respect to piston 35. Similar structure will be seen at 40 generally for piston 36 and likewise can be seen for the pistons in the lower half of the drawing.

FIGURE 2 illustrates a desirable arrangement of the cylinders within the pump body 25. In FIGURE 2 suflicient teeth are shown on gear 26 to illustrate how it meshes with gear 27, and broken lines are then used to illustrate the circle formed by the balance of the gear teeth.

Between any two pistons in each cylinder is provided a combined inlet outlet port 41 and with suitable ball check valves as at 42 for the outlet side and 44 for the inlet side. Obviously liquids provided through tube 21 will be drawn into the cylinder through inlet 41 whenever the pistons are moving away from each other and the ball 43 moving readily off its seat. At the same time during this suction period no materials that have gone past ball check 42 would be allowed to be drawn back into the device as the ball will be on its seat as shown therein. Conversely, in the lower half of the drawing, the two pistons will be seen to be moved toit ward each other as far as possible and the ball check leading to pipe 18 is off its seat.

The pistons may all be suitably partially cut away at theends adjacent to another piston, here shown illustratively as a step-like arrangement as shown at specifically for piston 36 and as will be seen to be true for all the pistons, so that the portion of the piston facing the center of the circle of the pump body where the inlet port 41 is, will not be blocked by the pistons even though their ends approach each other rather closely as shown by the pistons 46 and 47 at the bottom of the structure shown in FIGURE 1.

As shown also in FIGURE 1, the pistons 46 and 47 have secured to them the balls 48 and 49 which extend beyond pump body 25. These balls are contained in the partial sockets formed in the plate structure illustrated in more detail in FIGURES 3 and 4. 1

As shown in FIGURES 3 and4, a plate such as the one 50 is provided with a plurality of formations comprising openings and formed portions of the plate making a half a socket of larger size as shown at 51 and a plurality of similar smaller formations except that the socket opening and the socket half is slightly elongated radially as shown at 52. Between these larger socket halves 51 and the smaller socket halves 52 are nut and bolt assemblies 54 which secure a plate such as the one 50 to its mating'plate 55 to form a wobble plate assembly, as shown in FIGURE 4. Within the larger socket portions formed by the plates 50 and 55 being held together by nut and bolt assemblies 54 are the large balls 56 while smaller balls such as the one 48 shown secured to the piston 46 are positioned in the elongated sockets 52. In the center the two plates together form the large partial socket arrangement 57. A plate and ball assembly designated 58 in FIGURE 1 is provided at the other end of casing 10; it is like the plate assembly made up of plates 50-55 shown in FIGURES 3 and 4. Thus,'the balls 56 are free to roll in their socket portions 51 while the balls 48 are permitted to swivel and. slide in their elongated socket portions 52. The plane assembly made up of the plates 50 and 55 is referred to generally as plate 59 in FIGURE 1 in order to simplify discussion of operation.

The plate assembly 59 rides on a large bearing member 60 which is embraced by the large socket portion 57 at the center of plate assembly 59. Similar structure appears at 61 on the pipe 21. End plate 15 will be seen to have a cam structure 62 formed integrally therewith and therefore held stationary with the end plate 15 with respect to housing 10. On pipe 18, however, a bearing member 64 will be seen to serve as a journal for a movable cam 65. Cam 65 is provided with suitable gear teeth as at 66 which mesh with the teeth of a spur gear 67 in FIGURE 1. Spur gear 67 is suitably secured to a shaft 68 which extends through and is rotatably supported by a suitable bearing as at 69 in end plate 11. Means to facilitate turning gear 67 may be provided in any acceptable form such as the knob 70. Shaft 68 is sealed with respect to the end plate 11 by means of conventional seal of any suitable nature such as the one shown illustratively at 71 herein.

Knob may be associated with any suitable sort of an indicator and calibrated dial plate on the exterior of end plate 11 in a manner that is well known to those skilled in making controls of various kinds and therefore neither discussed or illustrated in detail herein. When the high points on the cam plates are opposite to each other or aligned longitudinally, the pump is producing its greatest'output. When the highest point on one cam is directly opposite the lowest point on the other cam, the pump is in a zero output condition. The area between these two positions rnay be suitably calibrated to indicate percentage of pump output or specific quantities of volumetric output of the pump.

1 point of maximum separation.

Clearly also, more elaborate valving formation could be provided in order to handle specific liquids that are extra viscous or otherwise present problems, but the broad principle of varying the pumping capacity of the pump remain the same. Also neither shown nor discussed are specific means for mounting the pump as these may be adapted to any particular situation required and are of a conventional nature. Normally such mounting constitutes legs molded integrally with or securely fastened to the casing 16 or any other suitable means with which those skilled in the art are familiar.

Operation.

As shaft 28 is driven by any suitable source of power and with the control knob 70 holding cam plate 65 in the poistion shown in FIGURE 1, the pump will be at maximum output per revolution. A reference to the top diagram of FIGURE 5, labeled output, will illustrate the reaction of any two opposed pistons. Actually, of course, as shown in FIGURE 2, there are five pairs of pistons operating oppositely to each other. 100% output on the diagram in FIGURE 5, however, illustrates one complete revolution of pump body 25 with respect to any given pair of pistons. At zero degrees the pistons would be in the position illustrated in FIGURE 1 by pistons 46 and 47. As the gear 27 is driven by shaft 28, gear 26 responds rotating the pump body with respect to the cam plates. As the pistons move toward a lower portion of their respective cam plates the two pistons are moved away from each other and the suction or intake period of the pump is created. When the pistons have reached the point illustrated by pistons 35 and 36 in FIGURE 1, they are at the point labeled that is to say at their The rectangles in the diagram labeled 100% output that correspond in position to pistons 35 and 36 are marked with those numbers. Thereafter, rotation of pump body 25 moves the two pistons toward each other causing the liquid that has been drawn in between the pistonsto be discharged. At the end of 360 of rotation, the cycle is completed and that pair of pistons is about to begin the suction portion of a second cycle.

At 50% output the cam plate 65 is rotated 90 with respect to cam plate 62. With the cam plates 65 and 62 positioned as set out, one piston will be at its point of innermost thrust with the balls 56 engaged with the highest point of the cam plate at the instant that the balls of the other wobble plate are at a point half-way between the lowest point and the highest point on its cam. The output of the pump is illustrated in the diagram of FIG- URE 5 labeled 50% output. As shown therein, the two pistons in the beginning are moving in the same direction so that the effective area between them remains constant. At the time when the piston at the right has reached its point of innermost travel, however, the piston at the left will not have reached its point of farthest travel from the center. At this instant, neutral stops and suction starts as indicated by labels on the diagram. The right hand piston now begins to move away from the center of the pump while the lefthand piston continues to move away from the center of the pump and there is some suction action during this portion of operation. This is true until the center part of the diagram is reached, whereupon the lefthand piston has reached its point of most extreme movement away from the center of thepump, in other words, it is engagedwith the lowest portion of its cam. The righthand piston on the other hand is still moving away from the center of the pump and hence for a brief period both pistons are moving in the same direction as shown by the next two blocks marked neutral and neutral stops discharge starts. Atthis latter point, the piston at the right has passed its'point of most distant removal from the center and starts toward the center of the pump. The piston at the left, on the other hand, is still moving toward the center and hence there is a discharge action down to the point at the bottom of the diagram at which point the lefthand piston has reached its point nearest to the center of the pump and will thereafter start moving away from it. This begins a new cycle as the pistons are back to the position shown at the top of the diagram.

The final diagram illustrates zero percent output and is so labeled. Under the conditions of having the two plates exactly oppositely disposed with respect to each other so that the highest point on one is directly opposite to the lowest point on the other, the pump will never either take in fluid or discharge it. As the pump body 25 is rotated about the pipes 18 and 21, the lefthand piston is always moving away from the center while the righthand piston moves toward it and vice versa. Under these conditions, the clearance between the two pistons remains constant. As a result there is never any suction or discharge action taking place between any two of the pistons hearing this status of the two cam plates 62 and 65. Between zero output and 50% output, there of course may be a wide range of adjustment and similarly between 50% output and 100% output. The number of different outputs to which the pump may be adjusted is controlled or limited simply by the fact that in order to produce a noticeable difference at all, the cam plates must be moved somewhat with respect to each other and hence the pump does not literally have the apparent infinite variation that the structure theoretically possesses. On the other hand, the output may be altered through an exremely large number of well controlled and slight differences.

Knob 70 may be provided with means for holding it against movement to insure that any adjusted position of cam plate 65 will not be altered through frictional reaction between the cam plate and the rotating pump body. Any ofnumerous conventional structures such as friction clutches, detents, serrations or the like, may be employed to minimize or prevent such undesired movement, and therefore, no special structure is actually illustrated or described herein.

It is apparent that manymodifications and variations of this invention as hereinbefore set forth may be made without departing from the spirit and scope thereof. The specific embodiments described are given by way of example only and the invention is limited only by the terms of the appended claims.

What is claimed is:

1. A metering pump comprising: a housing, opposed inlet and outlet pipes supported on said housing, a pump body rotatably supported by said inlet and outlet pipes, at least one cylinder formed in said pump body in an area outside the area occupied by said inlet and outlet pipe, oppositely acting one-way check valves interposed between said inlet pipe and outlet pipe and said cylinder, pistons in said cylinder, means journalled in said housing and engaging said pump body for rotating it in said frame,

means secured to said housing and said pistons to reciprocate them a fixed amount for each revolution of said pump body, and means secured to said housing for varying the timing of the reciprocation of one of said pistons with relation to the other of said pistons to alter the maximum and minimum clearances therebetween during any given revolution of said pump body.

2. The structure of claim 1 in which said means for reciprocating said pistons are wobble plates movably secured to said housing and said pistons, and earns secured to said housing and engaging said wobble plates, one of said cams being stationary and the other rotatable.

3. The structure of claim 1 in which said pistons are cut away at their ends adjacent said one-way check valves. 4. A metering pump comprising, a case, a pump body rotatably supported inside said case, at least four pairs of opposed reciprocating metering elements within said pump body, means journalled in said case and engaging said pump body for rotating said pump body, inclined surfaces inside said case at the ends of said pump body, Wobble plates secured to said metering elements and engaging said inclined surfaces, hollow cylindrical members secured to said case and extending into said pump body in sealing rotatable relationship therewith, said hollow cylindrical members comprising the inlet and outlet for said pump body, one of said inclined surfaces being r0 tatable within said case, a gear secured to said rotatable inclined surface, a shaft extending through said case rotatably, a gear secured to said shaft and engaging said gear secured to said inclined surface, means secured to said shaft outside said case to facilitate rotating it as far as necessary to produce 180 of rotation of said inclined surface to which said gear is secured and one-way valving interposed between said inlet and said metering elements and said outlet and said metering elements, said wobble plates being slidably supported by said hollow cylindrical members, whereby said wobble plates Wobble at determined locations in said case.

5. A metering pump comprising, a case, a pump body rotatably supported inside said case, at least four pairs of opposed reciprocating metering elements within said pump body, means journalled in said case and engaging said pump body for rotating said pump body, inclined surfaces inside said case at the ends of said pump body, wobble plates secured to said metering elements and engaging said inclined surfaces, hollow cylindrical members secured to said case and extending into said pump body in sealing rotatable relationship therewith, said hollow cylindrical members comprising the inlet and outlet for said pump body, one of said inclined surfaces being rotatable within said case, a gear secured to said rotatable inclined surface, a shaft extending through said case rotatably, a gear secured to said shaft and engaging said gear secured to said inclined surface, means secured to said shaft outside said case to facilitate rotating it and one-way valving interposed between said inlet and said metering elements and said outlet and said metering elements, said one-way valving comprising, a pair of check valves for each pair of opposed reciprocating metering elements, and the other of said inclined surfaces is fixed in relation to said case, said wobble plates being slidably supported by said hollow cylindrical members, whereby said wobble plates wobble at determined locations in said case.

6. The structure of claim 5 in which said check valves are independently operating valves and said opposed reciprocating metering elements are cut away at their facing ends and on the side near the center of said pump body.

References Cited by the Examiner UNITED STATES PATENTS 1,669,976 5/28 De Leeuw. 1,908,612 5/33 Johnson l03162 2,561,519 7/51 Leech 103-37 2,565,582 8/51 White 103-37 2,617,360 11/52 Barker 10337 X 2,633,802 4/53 Parilla 103-37 2,691,350 10/54 Greer 10337 FOREIGN PATENTS 567,840 12/23 France.

951,413 10/56 Germany.

771,796 4/57 Great Britain.

592,820 5/59 Italy.

LAURENCE V. EFNER, Primary Examiner.

JOSEPH H. BRANSON, 111., Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 191 S 2 June Kenneth D Hughes Column 3, llne 40, for "plane" read plate 4 line 5, for "remain" read remains column 5, for "frame" read housing Signed and sealed this 21st day of December 1965.,

(SEAL) Attest:

ERNEST W. SWIDER Attesting Officer column line 56,

EDWARD J. BRENNER Commissioner of Patents 

1. A METERING PUMP COMPRISING: A HOUSING, OPPOSED INLET AND OUTLET PIPES SUPPORTED ON SAID HOUSING A PUMP BODY ROTATABLY SUPPORTED BY SAID INLET AND OUTLET PIPES, AT LEAST ONE CYLINDER FORMED IN SAID PUMP BODY IN AN AREA OUTSIDE THE AREA OCCUPIED BY SAID INLET AND OUTLET PIPE. OPPOSITELY ACTING ONE-WAY CHECK VALVES INTERPOSED BETWEEN SAID INLET PIPE AND OUTLET PIPE AND SAID CYLINDER, PISTONS IN SAID CYLINDER, MEANS JOURNALLED IN SAID HOUSING AND ENGAGING SAID PUMP BODY FOR ROTATING IT IN SAID FRAME, MEANS SECURED TO SAID HOUSING AND SAID PISTONS TO RECIPROCATE THEM A FIXED AMOUNT FOR EACH REVOLUTION OF SAID PUMP BODY, AND MEANS SECURED TO SAID HOUSING FOR VARYING THE TIMING OF THE RECIPROCATION OF ONE OF SAID PISTONS WITH RELATION TO THE OTHER OF SAID PISTONS TO ALTER THE MAXIMUM AND MINIMUM CLEARANCES THEREBETWEEN DURING ANY GIVEN REVOLUTION OF SAID PUMP BODY. 